Microchip-based synthesis and total analysis systems (μSYNTAS): chemical microprocessing for generation and analysis of compound libraries

Mitchell, Michael C.; Spikmans, Val; Manz, A.; Mello, Andrew J. de

doi:10.1039/b009037i

Cited by 76 publications

(53 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…4,20 In this paper, we introduce a new concept of a dynamic micromixer (Fig. 1), which combines the concepts of parallel [14][15][16]26 multi-lamination12 and hydrodynamic focusing.18 , 27 This dynamic mixer composed of 200 µm wide and 80 µm high microchannels was fabricated from poly-methylmethacrylate (PMMA) materials 28 or polydimethylsiloxane (PDMS)8 (see ESI † ). There are three geometrically defined sections in the device, including: (i) a hydrodynamic focusing region where reactant and isolation streams are introduced into the device through the nine inletting microchannels, (ii) a linear microchannel for controlled mixing, and (iii) a triple-branched junction for collecting the resulting reaction mixtures and bypassing the sheath streams.…”

mentioning

confidence: 99%

A dynamic micromixer for arbitrary control of disguised chemical selectivity

et al. 2008

View full text Add to dashboard Cite

A new type of dynamic micromixer combining the concepts of parallel multi-lamination and hydrodynamic focusing was developed for arbitrary control of disguised chemical selectivity.Microreactors are microscopic reaction settings that exhibit unique properties versus traditional macroscopic environments: advantages of microreactors include reduced reagent consumption, high surface-area-to-volume ratios and improved control over mass and heat transfer. [1][2][3][4][5][6][7][8] In addition, fluidic physical phenomena in the microreactors are dramatically different from those observed in the macroscopic reaction apparatuses. [9][10][11] For instance, the inertial effect in the microfluidic environment is negligible (due to a low value of Reynolds number, Re), and thus fluid transport is dictated by fluid viscosity, leading to laminar flow in microchannels. A microfluidics-based reactor is known to be a turbulence-free system, in which diffusion-driven mixing is relatively slow. As a result, one of the most challenging issues in the field of microreactor design is to facilitate mixing in stand-alone devices. Over the past decades enormous efforts have been devoted to develop micromixers (one type of microreactor) that can be categorized into either active or passive ones. 12 Unlike active micromixers, passive ones13 do not require external power, are often composed of robust channel geometry or microstructures, and are developed upon straightforward concepts of increasing contact surfaces and/or shortening the distance for diffusion among different streams. For example, devices based on parallel14 -16 multi-lamination 12 have been developed to achieve efficient mixing. † Mixing may impact reaction outcomes. 17,18 A good example is the diazo coupling reaction 19 between 4-sulfono-benzenediazonium (1) and 1-naphthol (2) under alkaline conditions at room temperature. This reaction is known as a fast competitive consecutive reaction 20 (Scheme 1), where the selectivity between the two major reaction products (i.e., monosubstituted product 3 and disubstituted product 4) is not only determined by intrinsic reaction kinetics 21 (k 1 = 1.2 × 10 7 M −1 s −1 and k 2 = 2 × 10 3 M −1 s −1 ) but also affected by the mixing rates. When reactants 1 and 2 are mixed in a macroscopic setting, the reaction solution is first fragmented by stir-induced turbulence. No matter what mixing approach (e.g., hand mixing or mechanical stirring) is applied, in the best case scenario, the mean radii of the fragmentized solutions are approximately in the range of 100 to 1000 µm, 22,23 leading to a mixing time ranging from a millisecond to seconds. Consequently, the fast reaction between the 1 and 2 happens prior to complete homogeneous mixing to give a complicated reaction mixture containing reactant 2 and products 3 and 4. This phenomenon is known as the disguised chemical selectivity. 20,24,25 In order to avoid the undesired disguised chemical selectivity, micromixers exhibiting fast mixing rates have been developed. 4,20 In this paper,...

show abstract

mentioning

confidence: 99%

A dynamic micromixer for arbitrary control of disguised chemical selectivity

et al. 2008

View full text Add to dashboard Cite

show abstract

“…[167] In contrast with conventional batch systems, the use of MF to study and optimize the fabrication of a wide range of nanoparticles is attracting more and more attention [167] and their use for chemical synthesis gained a quick development with notable contributions from researchers at GlaxoSmithKline (UK), [168] Massachusetts Institute of Technology (USA), [169] the Institut für Mikrotechnik Mainz (Germany) [170] and Imperial College London (UK). [171] Since the first use of MF to prepare Cd nanoparticles on a lab-on-a-chip device, [172] advancement in the area of chemical synthesis of nanomaterials has been accelerated over the past decade. [39] Since then, various nanoparticles such as metal, [173] metal oxide, [174] semiconductors, [175] organic, [176] inorganic, etc., have been synthesized in MF systems, for example CdSe, Cds, Ti 2 O, boehmite, Au, Co, Ag, Pd, Cu, BaSO 4 , and CdSe − ZnS core-shell nanoparticles.…”

Section: Microfluidic Synthesis Of Nanoparticlesmentioning

confidence: 99%

Synthesis, Functionalization, and Design of Magnetic Nanoparticles for Theranostic Applications

Mosayebi

Kiyasatfar

Laurent

2017

Adv Healthcare Materials

192

171

View full text Add to dashboard Cite

In order to translate nanotechnology into medical practice, magnetic nanoparticles (MNPs) have been presented as a class of non‐invasive nanomaterials for numerous biomedical applications. In particular, MNPs have opened a door for simultaneous diagnosis and brisk treatment of diseases in the form of theranostic agents. This review highlights the recent advances in preparation and utilization of MNPs from the synthesis and functionalization steps to the final design consideration in evading the body immune system for therapeutic and diagnostic applications with addressing the most recent examples of the literature in each section. This study provides a conceptual framework of a wide range of synthetic routes classified mainly as wet chemistry, state‐of‐the‐art microfluidic reactors, and biogenic routes, along with the most popular coating materials to stabilize resultant MNPs. Additionally, key aspects of prolonging the half‐life of MNPs via overcoming the sequential biological barriers are covered through unraveling the biophysical interactions at the bio–nano interface and giving a set of criteria to efficiently modulate MNPs' physicochemical properties. Furthermore, concepts of passive and active targeting for successful cell internalization, by respectively exploiting the unique properties of cancers and novel targeting ligands are described in detail. Finally, this study extensively covers the recent developments in magnetic drug targeting and hyperthermia as therapeutic applications of MNPs. In addition, multi‐modal imaging via fusion of magnetic resonance imaging, and also innovative magnetic particle imaging with other imaging techniques for early diagnosis of diseases are extensively provided.

show abstract

“…24 This led to a considerable drive in the field of microfluidic technology, with notable contributions from GlaxoSmithKline, 25 Massachusetts Institute of Technology, 26 and University College London. 27 Consequently, over recent years, microreaction technology has become one of the most rapidly developing research fields in synthetic and process chemistry. These devices have evolved from relatively simplistic channel networks used for basic chemical processes, right through to complex designs for use in multi-step syntheses.…”

Section: Microfluidic Technologymentioning

confidence: 99%